Piston machine

ABSTRACT

The invention relates to a piston machine comprising two (or more) housing parts ( 3   a,    3   b ), which are each in the shape a circular cylinder segment, but which are joined to each other in such a way that the housing parts are rotated 180° with respect to each other, and which enclose a common cavity and each have a dual piston plate ( 1, 2 ), wherein the dual piston plates are associated with the respective housing part and driven separately and synchronously in opposite directions. The dual piston plates, together with the respective adjacent angled side wall ( 15, 16 ) of the housing part, the side wall having inlet and outlet valves ( 18   a/b,    19   a/b ), define two outer working chambers (A 1  and A 2 ) and one (or more) inner working chambers (A 3 ) are defined between the dual piston plates ( 1, 2 ), the one or more inner working chambers having inlet and outlet valves ( 18   c,    19   c ) formed in a rear housing wall ( 13 ) at the height of an imaginary separating line X between the housing parts ( 3   a,    3   b ). The piston machine thus formed, which can be operated as a pump, compressor, or expansion motor or as a combination thereof, is characterized by variable, efficient usage possibilities, a low dead volume, a correspondingly high efficiency, a compact and space-saving construction associated with low component expense, and a mass balance that is optimal due to the opposite synchronous drive of the dual piston plates offset by 180° from each other together with smooth running and correspondingly long service life.

The invention relates to a piston machine which comprises a housing having a substantially circular-cylinder-segment-like hollow space and first and second inlet and outlet valves which are provided on the inclined side walls and a pivotable dual piston plate which delimits variable operating spaces and which is connected to a rotary cylinder which is supported in the housing and which is driven by means of a crankshaft journal which is guided in a connection rod loop.

A piston machine of the above-mentioned type is known from DE 102008040574 A1. The dual piston plate which is arranged in a substantially circle-segment-like housing is pivotably supported by means of a rotary cylinder which is constructed thereon and divides the housing into two operating chambers which are separated from each other and which are each provided with inlet and outlet valves. The driving of the dual piston plate is carried out by means of a connection rod which is connected to the rotary cylinder and which is constructed as a connection rod loop in the guiding groove of which a crankshaft journal of a crankshaft engages. The connection rod loop may be arranged in a 180° angular position or in a 0° angular position or in a different angular position with respect to the dual piston plate. In the same manner, it is possible for the connection rod loop to be integrated directly in an end face of a thicker dual piston plate in order thus to be able to achieve a particularly compact structure for the piston machine. Furthermore, it is possible, on the periphery of one and the same rotary cylinder, to fit two or more dual piston plates which each divide a circle-segment-like housing portion into two operating chambers. Furthermore, a plurality of housing portions with dual piston plates pivotably supported therein may also be arranged one behind the other. In both cases, the driving can be carried out by means of only a single connection rod loop which is arranged separately or which is integrated into the dual piston plate, in order thus to ensure an effective and space-saving construction with a plurality of operating chambers.

An object of the invention is to develop a piston machine of the type mentioned in the introduction in such a manner that it can be operated in a compact, space-saving construction with greater efficiency.

According to the invention, the object is achieved with a piston machine which is constructed according to the features of patent claim 1.

Advantageous developments of the invention are set out in the dependent claims.

The central notion of the invention involves the construction of a piston machine which is operated with dual piston plates and which comprises at least two circular-cylinder-segment-like housing portions but which are joined together in a state rotated through 180° and which surround a common hollow space and which have dual piston plates which are separately associated with each housing portion and which are driven synchronously in opposing directions and which are orientated parallel with each other and which define, with the adjacent inclined side wall of the housing, which wall has inlet and outlet valves, a first and second external operating chamber and internal operating chambers which are located between the dual piston plates and which have inlet and outlet valves which are formed in a housing rear wall at the height of a notional separation line X between two adjacent housing portions. The volume of an internal operating chamber corresponds to the common volume of the two external operating chambers.

The piston machine, which is constructed in this manner and which can be operated as a pump, compressor or expansion motor or as a combination thereof, is distinguished by variable, efficient possibilities for use, a small dead volume and a correspondingly high degree of efficiency, a compact and space-saving structure which involves little component complexity and, owing to the opposing synchronous driving of the dual piston plates which are arranged in a state offset through 180° relative to each other, optimum mass balancing with a round path and accordingly long service-life.

In another embodiment of the invention, the dual piston plates are driven by means of a common drive shaft and separate crankshafts having crankshaft journals which act on a connection rod loop, the crankshafts being connected to each other by means of a toothed gear mechanism in order to produce a synchronous and oppositely directed pivot movement of the dual piston plates.

The connection rod loop (piston loop) which is provided to transmit force to the dual piston plate is an integral component of the respective dual piston plate, by the crankshaft journal of the respective crankshaft engaging in a guiding groove which is constructed in an end face of the dual piston plate and forming a piston loop therewith.

In another embodiment of the invention, there may be fitted to a rotary cylinder which is connected to the respective dual piston plate and which is supported in the circular-cylinder-segment-like housing portion in a sealing manner another additional dual piston plate which is located in an auxiliary housing portion which adjoins the relevant housing portion and which has a circular-cylinder-segment-like operating space in order to define one or more auxiliary operating chambers which are constructed with inlet and outlet valves. The other additional dual piston plates—when the volume of the auxiliary housing portions is adapted accordingly—may have a length which is the same as or different from the dual piston plates.

Embodiments of the invention will be explained in greater detail with reference to the drawings, in which:

FIG. 1 is a sectioned view of the piston machine illustrated in FIG. 4, with two dual piston plates which are arranged in a common housing, driven directly by means of an integral connection rod loop and located in an initial position on opposing side walls;

FIG. 2 shows the piston machine according to FIG. 1 in an intermediate position of the two dual piston plates at the time of the construction of two external operating chambers and one central operating chamber;

FIG. 3 shows the piston machine according to FIG. 1 in a central end position of the two dual piston plates on a notional separation line;

FIG. 4 is a sectioned side view of the piston machine illustrated with the drive;

FIG. 5 is another expanded embodiment of the piston machine according to FIG. 1 having other dual piston plates which are provided in a state offset in a 180° angular position on the rotary cylinder and which are arranged in another housing portion; and

FIG. 6 is a sectioned view of a piston machine having three dual piston plates which are arranged in a common housing.

According to FIGS. 1 to 3, the two dual piston plates 1 and 2 are connected to a rotary cylinder 6 which is supported in the housing 3 so as to be able to be rotated about a rotation axis 4 by means of bearings 5 and have at an end face a guiding groove 7 in which the crankshaft journal 8 of a crankshaft 10 which is connected to a drive shaft 9 engages. The guiding groove 7 acts as a connection rod loop or piston loop which is consequently an integral component of the dual piston plate 1, 2. The two crankshafts 10 which are operationally connected to the respective dual piston plate 1, 2 are, as shown in FIG. 4, connected to each other by means of a toothed gear mechanism 26 so that the dual piston plates 1, 2 can be driven synchronously and in mutually opposing directions and can be moved in the housing portions 3 a, 3 b which are constructed in the form of a circular cylinder segment (piece of cake).

The housing 3 which is constructed in one piece comprises—indicated by a dashed separation line X—two housing portions 3 a, 3 b which are, however, joined to each other in a state rotated through 180° and which each have a substantially circle-segment-like cross-section and in which the rotary cylinders 6 of the dual piston plates 1 and 2 are supported once on the upper housing wall 11 and once on the lower housing wall 12.

The housing 3 or the hollow space surrounded by the housing is in the form of two identically sized, oppositely adjacent circular cylinder segments (in the shape of a piece of cake). The housing 3 further comprises a housing rear wall 13 and a housing cover 14 and a first side wall 15 and a second side wall 16. The two dual piston plates 1, 2 which are orientated parallel with each other in each position are in the initial position (FIG. 1) on the respective side wall 15, 16 and almost strike each other in the end position

(FIG. 3) at the separation line X. Inlet valves 18 a, 18 b, 18 c and outlet valves 19 a, 19 b, 19 c are arranged in the two side walls 15, 16 and in the housing rear wall 13 at the height of the separation line X. Owing to a synchronous but oppositely directed rotational movement of the two crankshaft journals 8 in accordance with the arrow 17 a, 17 b, the two dual piston plates 1, 2 are moved towards each other as far as a location near the separation line X and moved away from each other as far as a location near the side walls 15, 16.

The piston machine which is constructed in this manner can be operated as a compressor, as a pump or as a motor. For example, during operation as a pump, a conveying medium which is located in the internal large operating chamber A3 (FIG. 3) between the two dual piston plates 1, 2 and which is previously drawn in via the inlet valve 18 c, is discharged again -from the operating chamber A3 during the pivot movement of the dual piston plates 1, 2 in the direction of the separation line X according to FIGS. 2 and 3. During this pivot movement (discharging), a conveying medium is drawn in at the same time via the inlet valves 18 a, 18 b into the two external (small) operating chambers A1 and A2 which are formed between the dual piston plates and 2 and the side walls 15 and 16, respectively. During the subsequent movement of the two dual piston plates 1, 2 in the direction of the side walls 15, 16, the conveying medium which was previously drawn into the operating chambers A1, A2 is discharged through the outlet valves 19 a, 19 b and, at the same time, conveying medium is drawn via the inlet valve 18 c into the large operating chamber A3. In this manner, with two cooperating dual piston plates 1, 2 and three operating chambers A1, A2 and A3, an effective conveying operation is ensured in one and the same housing 3. The maximum volume of the two small external operating chambers A1 and A2 corresponds to the maximum volume of the large, internal operating chamber A3. With the same high level of efficiency, the piston machine described above can also be operated as a compressor or as an expansion motor or as a combination thereof. For example, the central—large—operating chamber A3 can operate as an expansion motor whilst the other two external—small—operating chambers A1 and A2 can operate as a compressor or as a pump and be driven by the expansion motor. When the piston pump described is used as a compressor, the internal operating chamber A3 and an external (left) operating chamber A1 could be operated as a first compressor stage and the other external operating chamber A2 as a second compressor stage.

FIG. 5 shows another construction variant of the piston machine previously described in FIGS. 1 to 4 with reference to the example of a piston pump.

Accordingly, the housing 3 is in each case expanded in the region of the rotary cylinder 6 which is supported in a sealing manner here by means of an auxiliary housing portion 3 d, 3 e with a substantially circular-cylinder-segment-like operating space. In the auxiliary housing portion 3 d, 3 e, in the side walls 22, 23 of which an inlet valve 24 a, 24 b and an outlet valve 25 a, 25 b are provided, respectively, there is arranged another dual piston plate 20, 21 which is connected to the respective rotary cylinder 6 and which are driven at the same time with the first and second dual piston plate 1, 2. Four auxiliary operating chambers A5, A6 and A7, A8 are thereby produced and can also operate as a pump, compressor or expansion motor. In each case, in the embodiment according to FIG. 5, a plurality of advantageous application possibilities are conceivable. The other dual piston plates 20, 21 have in the embodiment according to FIG. 5 the same length as the first and second dual piston plates 1, 2. However, the length of these additional dual piston plates 20, 21 may also deviate from the length of the first and second dual piston plates 1, 2. That is to say, the additional dual piston plates may be shorter or longer than the first and second dual piston plates or may have a length which corresponds thereto. In the case of shorter dual piston plates 20, 21 and correspondingly smaller volumes of the auxiliary operating chambers, the piston machine described with reference to FIG. 5 could be operated, for example, very well as a multi-stage compressor or a multi-stage vacuum pump.

As shown in FIG. 6, the piston machine described with reference to FIGS. 1 to 4 having two circular-cylinder-segment-like housing portions 3 a, 3 b and two dual piston plates 1, 2 which are arranged therein can be freely expanded by means of additional housing portions which are arranged adjacent to each other but in a state rotated through 180° relative to each other and which have dual piston plates. The piston pump according to FIG. 6 has three housing portions 3 a, 3 b and 3 c having dual piston plates 1, 2, 27 which can be pivoted synchronously in a mutually parallel manner therein, but which are directly driven in opposing directions, two external (small) operating chambers A1, A2 and two internal (large) operating chambers A3, A4 of the same size being formed. The driving action is brought about in the same manner as described above with reference to FIGS. 1 to 4. Of course, this expanded construction variant, as illustrated with reference to FIG. 5, can also be constructed with auxiliary housing portions and corresponding dual-wing dual piston plates. The piston machine which is constructed in this manner can in turn be used as a multi-stage compressor, pump or motor or as a combination thereof.

LIST OF REFERENCE NUMERALS

-   1 First dual piston plate -   2 Second dual piston plate -   3 Housing -   3 a/b/c First to third housing portions -   3 d, 3 e Auxiliary housing portions -   4 Rotation axis -   5 Bearing -   6 Rotary cylinder -   7 Guiding groove (connection rod/piston loop) -   8 Crankshaft journal -   9 Drive shaft -   10 Crankshaft -   11 Upper housing wall -   12 Lower housing wall -   13 Housing rear wall -   14 Housing cover -   15 First (left) side wall -   16 Second (right) side wall -   17 a, 17 b Rotation direction of 8 -   18 a/b/c/d Inlet valves in 15, 16, 13 -   19 a/b/c/d Outlet valves in 15, 16, 13 -   20 Additional dual piston plate -   21 Additional dual piston plate -   22 Left side wall of 3 c, 3 d -   23 Right side wall of 3 c, 3 d -   24 a, 24 b Inlet valves in 22, 23 -   25 a, 25 b Outlet valves in 22, 23 -   26 Toothed gear mechanism -   27 Third dual piston plate -   X Separation line between 3 a and 3 b -   A1, A2 Small external operating chamber -   A3, A4 Large internal operating chambers -   A5, A6, A7, A8 Auxiliary operating chambers 

1. A piston machine which comprises a housing having a substantially circular-cylinder-segment-like hollow space and first and second inlet and outlet valves (18 a, 19 a; 18 b, 19 b) which are provided on the inclined side walls and a pivotable dual piston plate which delimits variable operating spaces and which is connected to a rotary cylinder which is supported in the housing and which is driven by means of a crankshaft journal which is guided in a connection rod loop, wherein the housing (3) is constructed from two or more circular-cylinder-segment-like housing portions (3 a, 3 b, 3 c) but which are integrally joined together in a state rotated through 180° and which form a common hollow space and which have dual piston plates (1, 2, 27) which are associated with each housing portion and which are driven synchronously in opposing directions and which are arranged parallel with each other and which define, with the adjacent inclined side wall (15, 16) an external operating chamber (A1, A2) and, between the dual piston plates (1, 2, 27), an internal operating chamber (A3, A4) having third and fourth inlet and outlet valves (18 c, 19 c; 18 d, 19 d) which are formed in a housing rear wall (13) at the height of a notional separation line X between the mutually adjacent housing portions (3 a, 3 b, 3 c).
 2. The piston machine as claimed in claim 1, wherein the total volume of the two external operating chambers (A1, A2) substantially corresponds to the volume of the internal operating chamber (A3, A4), wherein the volume of the external operating chambers (A1, A2) and the volume of the internal operating chambers (A3, A4) is of the same size.
 3. The piston machine as claimed in claim 1, wherein the dual piston plates (1, 2, 27) are driven by means of a common drive shaft (9) and two or more separate crankshafts (10) having crankshaft journals (8) which act on a connection rod loop, wherein the crankshafts (10) are connected to each other by means of a toothed gear mechanism (26) in order to produce a synchronous and oppositely directed, parallel pivot movement of the dual piston plates (1, 2, 27).
 4. The piston machine as claimed in claim 1, wherein the connection rod loop is an integral component of the respective dual piston plate (1, 2, 27), by the crankshaft journal (8) engaging in a guiding groove (7) which is constructed in an end face of the dual piston plate (1, 2).
 5. The piston machine as claimed in claim 1, wherein there is fitted to at least one of the rotary cylinders (6), which are connected to the first and/or second and/or third dual piston plate (1, 2, 27) and which are supported in the housing (3 a, 3 b, 3 c) in a sealing manner, at least one additional dual piston plate (20, 21) which is/are located in an auxiliary housing portion (3 d, 3 e) which adjoins the first to third housing portions (3 a, 3 b, 3 c) and which has a circular-cylinder-segment-like operating space and which define(s) additional auxiliary operating chambers (A5, A6; A7, A8) which are constructed with inlet and outlet valves (24 a, 25 a; 24 b, 25 b).
 6. The piston machine as claimed in claim 5, wherein the at least one additional dual piston plate (20, 21) has a length which is the same as or different from the first to third dual piston plates (1, 2, 27), wherein the volume of the auxiliary operating chambers (A5-A8) deviates from that of the external operating chambers (A1, A2) or is identical, respectively.
 7. The piston machine as claimed in claim 1, wherein it can be operated as a pump and/or compressor and/or expansion motor.
 8. The piston machine as claimed in claim 1, wherein a plurality of machines are arranged in disk form one behind the other. 